1. Field of the Invention
The present invention relates ladders and more particularly, to a combination hand truck ladder that can be used as a hand truck for moving things as well as a platform ladder for use in climbing.
2. Description of the Related Art
A conventional combination hand truck ladder, as shown in FIG. 1, comprises a front frame 1, a back frame 2 pivoted to the front frame 1 near the top side of the front frame 1, a plurality of platforms 3 respectively pivotally connected to the front frame 1 at different elevations, two links 4 respectively pivotally connected to the two distal ends of the rear side of each of the platforms 3, a rear transverse rod 6 inserted through a respective elongated slot 5 at the top side of each of the links 4 and pivotally connected to the back frame 2, two wheels 7 respectively pivotally connected to the bottom side of the back frame 2, a front transverse rod 9 fixedly fastened to the front frame 1 at the bottom side, and a carrier shell 8 pivoted to the front transverse rod 9.
When wishing to use this combination hand truck ladder as a platform ladder in climbing, the front frame 1 and the back frame 2 are extended out and stably supported on the floor. At this time, the links 4 are moved with the back frame 2 relative to the front frame 1 to hold the platforms 3 in horizontal, and the carrier shell 8 is closely received to the front frame 1. When wishing to use this combination hand truck ladder as a hand truck for carrying things, the front frame 1 and the back frame 2 are received together and tilted, letting the wheels 7 support the gravity weight of the whole assembly of the combination hand truck and ladder. At this time, the links 4 are forced to turn the platforms 3 downwards and to keep the platforms 3 closely received to the front frame 1, and the carrier shell 8 is extended out of the front frame 1 for carrying things. Thus, the user can hold the top side of the front frame 1 and push the whole assembly of the combination hand truck ladder on the floor with less effort.
The aforesaid combination hand truck ladder is functional, however it wears quickly with use.